| Cover Page Cover Page | Jun. 05, 2020 |
| Cover [Abstract] | |
| Document Type | 8-K |
| Document Period End Date | Jul. 23, 2020 |
| Entity Incorporation, State or Country Code | DE |
| Entity File Number | 001-34249 |
| Entity Tax Identification Number | 95-0725980 |
| Entity Address, Address Line One | 1912 Farmer Brothers Drive, |
| Entity Address, City or Town | Northlake, |
| Entity Address, State or Province | TX |
| Entity Address, Postal Zip Code | 76262 |
| City Area Code | 888 |
| Local Phone Number | 998-2468 |
| Written Communications | false |
| Soliciting Material | false |
| Pre-commencement Tender Offer | false |
| Pre-commencement Issuer Tender Offer | false |
| Title of 12(b) Security | Common Stock, $1.00 par value |
| Trading Symbol | FARM |
| Security Exchange Name | NASDAQ |
| Entity Emerging Growth Company | false |
| Entity Registrant Name | FARMER BROTHERS CO |
| Entity Central Index Key | 0000034563 |
| Amendment Flag | false |
